Appendix 4 - Gas Cylinder Heel Triggers Industry

Gas Cylinder Size

Full 

Weight of 

Gas (lb)

Heel 

Fraction

Weight of 

Heel (lb) 

(See 

Explanat

ory Note 

in Cell 

54) 

5% of 

Heel 

Weight: 

Subpart I 

Heel 

Change 

Trigger 

Level (lb) 

(See 

Explanat

ory Note 

in Cell 

56)

MT CO2e 

Equiv. of 

5% of 

Heel

1% of 

Cylinder 

gas 

weight 

(lb)

% of Heel 

Weight

MT CO2e 

Equiv. of 

1% of 

Cylinder 

Weight 

2% of 

Cylinder 

gas 

weight 

(lb)

% of Heel 

Weight

MT CO2e 

Equiv. of 

2% of 

Cylinder 

Weight

3% of 

Cylinder 

gas 

weight 

(lb)

% of Heel 

Weight

MT CO2e 

Equiv. of 

3% of 

Cylinder 

Weight

5% of 

Cylinder 

Gas 

Weight 

(lb)

% of Heel 

Weight

50% of 

Gas Heel 

Weight

Range of 

Cylinder 

Changes 

at a 200 

mm Fab 

(Explanat

ory Note 

in Cell 

60)

Range of 

Cylinder 

Changes 

at a 300 

mm Fab 

(See 

Explanat

ory Note 

in Cell 

60) Assessment 

Report's 

3rd Assessment 

GWP100

C4F6 7X 19 STEEL 6.0 7.0% 0.4 0.020 0.000 0.060 15.0% 0.001 0.120 30.0% 0.001 0.180 45.0% 0.002 0.300 75.0% 0.200 GWP values

C5F8 7X19 STEEL 19.8 10.0% 2.0 0.100 0.000 0.198 9.9% 0.000 0.396 19.8% 0.000 0.594 29.7% 0.000 0.990 49.5% 1.000 3 to 5

c-C4F8 small 7X19 STEEL 15.3 10.0% 1.5 0.077 0.348 0.153 10.0% 0.695 0.306 20.0% 1.391 0.459 30.0% 2.086 0.765 50.0% 0.765 1 to 2 GWP values

CF4 ((513) 1.75 pounds 1.8 5.0% 0.1 0.004 0.011 0.018 20.0% 0.045 0.035 40.0% 0.091 0.053 60.0% 0.136 0.088 100.0% 0.044 15 to 25

CH2F2 7X19 STEEL 10.0 20.0% 2.0 0.100 0.025 0.100 5.0% 0.025 0.200 10.0% 0.050 0.300 15.0% 0.075 0.500 25.0% 1.000 2 to 5

Perfluoromethane 

(CF4) 5700

CH2F2 (625) 7X19 STEEL 7.0 20.0% 1.4 0.070 0.018 0.070 5.0% 0.018 0.140 10.0% 0.035 0.210 15.0% 0.053 0.350 25.0% 0.700 2 to 5

CH3F 7X19 STEEL 3.0 21.0% 0.6 0.032 0.002 0.030 4.8% 0.002 0.060 9.5% 0.004 0.090 14.3% 0.006 0.150 23.8% 0.315

CH3F 7X46 STEEL 15.0 13.0% 2.0 0.100 0.007 0.150 7.5% 0.010 0.300 15.0% 0.020 0.450 22.5% 0.031 0.750 37.5% 1.000 1 to 5

CH3F 7X19 STEEL 19.0 10.0% 1.9 0.095 0.006 0.190 10.0% 0.013 0.380 20.0% 0.026 0.570 30.0% 0.039 0.950 50.0% 0.950 1to 3 4 to 10

CH3F (83) 7X19 STEEL 10.0 21.0% 2.1 0.105 0.007 0.100 4.8% 0.007 0.200 9.5% 0.014 0.300 14.3% 0.020 0.500 23.8% 1.050

Perfluoroethane 

(C2F6) 11900

CHF3 7X19 STEEL 15.0 5.0% 0.8 0.038 0.205 0.150 20.0% 0.818 0.300 40.0% 1.636 0.450 60.0% 2.455 0.750 100.0% 0.375 3 to 5

Sulfur 

Hexafluoride 

(SF6) 22200

C2F6 9X51 STEEL 95.0 6.0% 5.7 0.3 1.5 1.0 16.7% 5.1 1.9 33.3% 10.3 2.9 50.0% 15.4 225 to 300 3 to 5

Nitrogen 

Trifluoride (NF3) 10800

C2F6 9x51 STEEL 100.0 5.0% 5.0 0.3 1.4 1.0 19.0% 5.4 2.0 40.0% 10.8 3.0 60.0% 16.2 300 to 400

Nitrogen 

Trifluoride (NF3) 10800

C2F6 (10) 950 pounds 950.0 6.0% 57.0 2.9 15.4 1.0 1.8% 5.7 19.0 33.3% 102.8 28.5 50.0% 154.2 225 to 300 3 to 5

Trifluoromethane 

(CHF3) (HFC-23) 12000

C3F8 9X51 STEEL 105.0 9.5% 10.0 0.5 2.0 1.1 10.5% 4.1 2.1 21.0% 8.2 3.2 31.5% 12.3 100 to 200

Perfluoropropane 

(C3F8) 8600

c-C4F8 9X51 STEEL 70.0 7.0% 4.9 0.2 1.1 0.7 14.3% 3.2 1.4 21.0% 6.4 2.1 42.9% 9.5 20 to 100

Perfluoropropane 

(C3F8) 8600

c-C4F8 9X51 STEEL 70.0 5.0% 3.5 0.2 0.8 0.7 20.0% 3.2 1.4 28.6% 6.4 2.1 60.0% 9.5 C4F8** 10000

c-C4F8 9X51 STEEL 51.0 10.0% 5.1 0.3 1.2 0.5 10.0% 2.3 1.0 20.0% 4.6 1.5 30.0% 7.0

c-C4F8 Y cylinder 1200.0 2.0% 24.0 1.2 5.5 12.0 50.0% 54.5 24.0 100.0% 109.1 36.0 150.0% 163.6 1 to 2 CH2F2 550

c-C4F8 clean 9X51 STEEL 109.3 2.0% 2.2 0.1 0.5 1.1 50.0% 5.0 2.2 100.0% 9.9 3.3 150.0% 14.9

c-C4F8 large 9X51 STEEL 50.0 10.0% 5.0 0.3 1.1 0.5 10.0% 2.3 1.0 20.0% 4.5 1.5 30.0% 6.8 2 to 3 CH2F2 550

c-C4F8 large 9x51 STEEL 44.0 10.0% 4.4 0.2 1.0 0.4 10.0% 2.0 0.9 20.0% 4.0 1.3 30.0% 6.0 2 to 3

CF4 7X19 STEEL 40.0 5.0% 2.0 0.100 0.3 0.400 20.0% 1.036 0.800 40.0% 2.1 1.200 60.0% 3.1 5 to 10 CH3F 150

CF4 9X51 STEEL 70.0 5.0% 3.5 0.2 0.5 0.7 20.0% 1.8 1.4 40.0% 3.6 2.1 60.0% 5.4 15 to 25 C4F6 27

CF4 9X51 STEEL 70.0 5.0% 3.5 0.2 0.5 0.7 20.0% 1.8 1.4 40.0% 3.6 2.1 60.0% 5.4 75 to 200 C4F6 27

CF4 Y cylinder 575.0 5.0% 28.8 1.4 3.7 5.8 20.0% 14.9 11.5 39.9% 29.8 17.3 59.9% 44.7 8 to 15 C5F8 Unknown

CF4 (2000psi) Y cylinder 720.0 5.0% 36.0 1.8 4.7 7.2 20.0% 18.7 14.4 40.0% 37.3 21.6 60.0% 56.0 5 to 10

CH2F2 9X51 STEEL 70.0 2.9% 2.0 0.1 0.0 0.7 35.0% 0.2 1.4 70.0% 0.4 2.1 105.0% 0.5 2 to 5

CHF3 7X19 STEEL 47.0 11.1% 5.2 0.3 1.4 0.5 9.0% 2.6 0.9 18.1% 5.1 1.4 27.1% 7.7 60 to 100

CHF3 9X51 STEEL 75.0 14.0% 10.5 0.5 2.9 0.8 7.1% 4.1 1.5 14.3% 8.2 2.3 21.4% 12.3

CHF3 Y cylinder 800.0 5.0% 40.0 2.0 10.9 8.0 20.0% 43.6 16.0 40.0% 87.3 24.0 60.0% 130.9 1 to 2

CHF3 (8) 7X19 STEEL 47.0 11.1% 5.2 0.3 1.4 0.5 9.0% 2.6 0.9 18.1% 5.1 1.4 27.1% 7.7 60 to 100

NF3 9X55 STEEL 48.0 5.0% 2.4 0.1 0.6 0.5 20.0% 2.4 1.0 40.0% 4.7 1.4 60.0% 7.1 200 to 300

NF3 9X55 STEEL 50.0 5.0% 2.5 0.1 0.6 0.5 20.0% 2.5 1.0 40.0% 4.9 1.5 60.0% 7.4 100 to 200

NF3 9X55 STEEL 50.0 4.0% 2.0 0.1 0.5 0.5 25.0% 2.5 1.0 50.0% 4.9 1.5 75.0% 7.4 10 to 20

NF3

Tube Trailer: 

4X1100 1100.0 10.0% 110.0 5.5 27.0 11.0 10.0% 54.0 22.0 20.0% 108.0 33.0 30.0% 162.0 25 to 35

NF3 (675) 9X55 STEEL 48.0 5.0% 2.4 0.1 0.6 0.5 20.0% 2.4 1.0 40.0% 4.7 1.4 60.0% 7.1

NF3 (812) Tonner 485.0 4.0% 19.4 1.0 4.8 4.9 25.0% 23.8 9.7 50.0% 47.6 14.6 75.0% 71.4 10 to 20

NF3 (971) 16 Pack 800.0 1.9% 15.2 0.8 3.7 8.0 52.6% 39.3 16.0 105.3% 78.5 24.0 157.9% 117.8 25 to 35

SF6 9X51 STEEL 40.0 6.0% 2.4 0.1 1.2 0.4 16.7% 4.0 0.8 33.3% 8.1 1.2 50.0% 12.1 3 to 10

SF6 9X51 STEEL 95.0 6.0% 5.7 0.3 2.9 1.0 16.7% 9.6 1.9 33.3% 19.2 2.9 50.0% 28.8 10 to 20

SF6 9X51 STEEL 100.0 5.0% 5.0 0.3 2.5 1.0 20.0% 10.1 2.0 40.0% 20.2 3.0 60.0% 30.3 1 to 40 20 to 25

SF6 9X51 STEEL 100.0 10.0% 10.0 0.5 5.0 1.0 10.0% 10.1 2.0 20.0% 20.2 3.0 30.0% 30.3

SF6 9X51 STEEL 100.0 6.0% 6.0 0.3 3.0 1.0 16.7% 10.1 2.0 33.3% 20.2 3.0 50.0% 30.3

SF6 (623) 9x51 STEEL 100.0 5.0% 5.0 0.3 2.5 1.0 20.0% 10.1 2.0 40.0% 20.2 3.0 60.0% 30.3 20 to 25

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Appendix 4 - Gas Cylinder Heel Triggers Industry

Cylinders with less than 20 

pounds of usable gas.

NOTES:

Column E provides actual measured heel factors from SIA member companies.

Column F provides the heel change trigger required under Subpart I for the measured, facility level heel factors (Col. D)

Columns V and W provide typical cylinder changes for the cylinder sizes in use at three SIA member companies. 

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